/Engine/Source/Runtime/NetworkReplayStreaming/NullNetworkReplayStreaming/Public/NullNetworkReplayStreaming.h
Sets a hint for how much data needs to be kept in memory. If set to a value greater than zero, a streamer implementation may free any in-memory data that would be required to go to a time before the beginning of the buffer.
virtual void SetTimeBufferHintSeconds ( const float InTimeBufferHintSeconds )